Air supply unit



FIG. 1 is a perspective view of an air supply unit, showing the new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left-side elevational view thereof;

FIG. 5 is a right-side elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof. 

The ornamental design for an air supply unit, as shown and described. 